Former general David Petraeus submitted his resignation as director of the CIA on Nov. 9, citing an extramarital affair. / Brendan Smialowski, Getty Images

by Oren Dorell, USA TODAY

by Oren Dorell, USA TODAY

A video shown Thursday to lawmakers investigating the attack on the U.S.Consulate in Libya provides no evidence of it starting with a spontaneous protest as the Obama administration insisted for days, according to a Republican senator at a hearing.

"It was very clear from day one that this was a terrorist attack," Sen. Saxby Chambliss, R-Ga., vice chairman of the Senate Intelligence Committee, told Fox News. "This would be obvious to anyone. That is very clear."

Susan Rice, U.S. ambassador the the United Nations, was dispatched by President Obama five days after the 9/11 attack to say it was a spontaneous spate of violence that emerged from a protest outside the consulate.

Rice said protesters were demonstrating against an anti-Islam video produced in the United States, and both Secretary of State Hillary Rodham Clinton and President Obama echoed that claim.

The State Department has since said that there was no protest and the White House has admitted the attack was a well-organized assault by al-Qaeda-linked terrorists timed to the anniversary of the 9/11 attacks.

Committee Chairwoman Sen. Dianne Feinstein, D-Calif., said testimony from former CIA director David Petraeus, expected Friday morning, is still needed because he went to Tripoli to see for himself what happened and to talk to people involved.

"I think to get his view will be very helpful," she said.

Asked whether Petraeus was directly involved in decision-making that night, Feinstein said "I don't know, and that's one of the things we're trying to find out."

Chambliss said Petraeus has been "straightforward with us" and he looked forward to hearing his testimony.

Petraeus, a retired four-star Army general, stepped down last week as CIA director because of an extramarital affair but has agreed to appear voluntarily before House and Senate investigative committees. Feinstein said her committee will hold at least two more fact-finding hearings before a public session to share what is learned.

Obama said at a news conference this week that Rice was repeating the scenarios provided to her by administration intelligence experts. Chambliss said he was skeptical of that claim and hopes Petraeus can shed light on it.

"She was saying exactly what the political shop at the White House told her to say," Chambliss said.

Four GOP senators have demanded the White House open up to Congress about the attack that killed a U.S. ambassador and three other Americans.

"You and your senior administration officials have not been forthcoming in providing answers to the many questions that have emerged," wrote Sen. John McCain, R-Ariz., in a letter also signed by Sens. Lindsey Graham, R-S.C., Kelly Ayotte, R-N.H., and Ron Johnson, R-Wis.

"The American people and their representatives in Congress need to understand what you knew about the Benghazi terrorist attack and when you knew it," the letter states.

Obama said at the news conference that his administration would cooperate with the investigation. He also criticized the GOP senators for questioning Rice, saying she has acted professionally.

Among the questions that the senators want answered:

â?¢ When were officials in the Obama administration - including the president - made aware of the true nature of the attack that killed U.S. Ambassador to Libya Christopher Stevens and three others.

â?¢ Why did Obama administration members insist days after the killings that they arose out of a protest over an anti-Islam video outside the consulate that never happened?

â?¢ Who was aware that requests from the ambassador for more security forces were denied, and why were they denied?

â?¢ Why was a decision made not to send military assets from air bases to put down the attack given that the Pentagon and White House reportedly had real-time video of what was happening from a drone surveillance plane?